The present invention relates to a pulse transmission line control system capable of selecting and controlling a transmission of an electrical signal pulse generated from an infrared code sent by an infrared remote control unit to a plurality of microcomputers that decode the electrical signal pulse and process the electrical signal pulse according to the infrared code.
Referring to FIG. 4, an apparatus will be described below that includes microcomputers having the function (hereinafter called xe2x80x9csystem for receiving an infrared remote control unit code pulsexe2x80x9d) of decoding an electrical signal pulse (hereinafter called xe2x80x9can infrared remote control unit code pulsexe2x80x9d) generated from an infrared code sent by an infrared remote control unit.
This apparatus is a combination of a new microcomputer G10 and an existing microcomputer H11. In this apparatus, when an infrared code is sent from an infrared control unit 3, an infrared ray detector 4 receives and converts the infrared code into an infrared remote control unit code pulse. The infrared remote control unit code pulse is transmitted to the microcomputers G10 and H11 over a pulse transmission line 5. Then, the microcomputer G10 or H11 decodes the infrared remote control unit code pulse to perform an operation requested by the infrared remote control unit 3 (requested by an operator).
However, in the apparatus in which all the microcomputers having the system for receiving an infrared remote control unit code pulse always receive the infrared remote control unit code pulse sent from the infrared ray detector as described above, while a microcomputer is performing a main operation, the same infrared remote control unit code pulse is also transmitted to the other microcomputers over the pulse transmission line and the other microcomputers also decode the infrared remote control unit code pulse. If the decode is effective, the other microcomputers operate according to the decoded information. As a result, it is feared that the apparatus according to prior art can perform unintended operation.
The present invention has been achieved in order to solve the problem and it is an object of the present invention to provide a pulse transmission line control system so that in an apparatus including a plurality of microcomputers each having a system for receiving an infrared remote control unit code pulse, one of the plurality of microcomputers has a function of controlling on/off operation of a switch and the other microcomputers are connected to a pulse transmission line through the switch, and the switch is controlled to transmit the infrared remote control unit code pulse only to one or more of the microcomputers that perform a process required for operation, thereby preventing a malfunction of the microcomputers.
The pulse transmission line control system according to the present invention is a system including a main microcomputer and a sub-microcomputer for performing a process according to an infrared code sent from an infrared remote control unit. The system includes an infrared ray detector for receiving the infrared code and converting the received infrared code into an electrical signal pulse, a pulse transmission line for transmitting the pulse to the main microcomputer and the sub-microcomputer, and a switch for connecting the sub-microcomputer to the pulse transmission line, wherein the main microcomputer selects and controls the switch according to whether or not transmission of the pulse to the sub-microcomputer is permitted and the pulse is transmitted to the sub-microcomputer when the transmission is permitted.
According to the present invention, the pulse transmission line control system is characterized in that a plurality of the sub-microcomputers are provided, each of the sub-microcomputers being provided with the switch, and the main microcomputer selects and controls the switch so that the pulse is transmitted only to one or more of the sub-microcomputers that perform a process required for operation.
Further, according to the present invention, the pulse transmission control system is characterized in that when the main microcomputer turns on the switch according to the received infrared code, the main microcomputer turns on the switch after the input of a pulse generated from the infrared code is completed.
Further, according to the present invention, in an apparatus including a plurality of microcomputers having a system for receiving an infrared remote control unit code pulse, a switch or switches can be controlled so that the infrared remote control unit code pulse is transmitted only to one or more of the microcomputers that perform a process required for operation and, as a result, a malfunction of the microcomputers can be prevented.